Reception of a low level RF signal often benefits from low noise and high precision operation. Noise and imprecision in such circuits has many different origins.
One common undesired signal is called an image frequency. The image signal is symmetrical to the desired frequency, relative to the local oscillator frequency.
The undesired component of the image frequency may cause image frequency interference, and this may produce undesirable content in the eventual received signal. Image frequency interference may reduce the amount of information that the channel can carry.
Different techniques have been used to reduce the effect of the image frequency interference.